Children's bouncers are used to provide a seat for a child that entertains or soothes the child by oscillating upward and downward in a way that mimics a parent or caretaker holding the infant in their arms and bouncing the infant gently. A typical children's bouncer includes a seat portion that is suspended above a support surface (e.g., a floor) by a support frame. The support frame typically includes a base portion configured to rest on the support surface and semi-rigid support arms that extend above the base frame to support the seat portion above the support surface. In these embodiments, an excitation force applied to the seat portion of the children's bouncer frame will cause the bouncer to vertically oscillate at the natural frequency of the bouncer. For example, a parent may provide an excitation force by pushing down on the seat portion of the bouncer, deflecting the support frame, and releasing the seat portion. In this example, the seat portion will bounce at its natural frequency with steadily decreasing amplitude until the bouncer comes to rest. Similarly, the child may provide an excitation force by moving while in the seat portion of the bouncer (e.g., by kicking its feet).
A drawback of the typical bouncer design is that the bouncer will not bounce unless an excitation force is repeatedly provided by a parent or the child. In addition, as the support arms of typical bouncers must be sufficiently rigid to support the seat portion and child, the amplitude of the oscillating motion caused by an excitation force will decrease to zero relatively quickly. As a result, the parent or child must frequently provide an excitation force in order to maintain the motion of the bouncer. Alternative bouncer designs have attempted to overcome this drawback by using various motors to oscillate a children's seat upward and downward. For example, in one design, a DC motor and mechanical linkage is used to raise a child's seat up and down. In another design, a unit containing a DC motor powering an eccentric mass spinning about a shaft is affixed to a bouncer. The spinning eccentric mass creates a centrifugal force that causes the bouncer to bounce at a frequency soothing to the child.
These designs, however, often generate an undesirable amount of noise, have mechanical components prone to wear and failure, and use power inefficiently. Thus, there remains a need in the art for a children's bouncer that will bounce repeatedly and is self-driven, quiet, durable, and power efficient. Furthermore, there is a need for an improved motion sensing apparatus that can be adapted for use with such bouncers in order to accurately and reliably sense the frequency of a bouncer's oscillation and actively provide feedback indicative of the sensed frequency to a control system configured to drive the motion of the bouncer based, at least in part, on the sensing apparatus' feedback.
In addition, existing bouncer designs are generally limited to providing a bouncing motion that is distinct from certain motions infants experience in a pre-natal state, or in a post-natal state, such as when being nursed or otherwise held closely by a parent or caregiver. As a result, the sensation resulting from the motion provided by exiting bouncer designs may not be soothing to all infants. Accordingly, there is a need in the art for an infant support configured to provide a soothing sensation to a child positioned within the infant support that differs from the typical bouncing motion provided by existing bouncer designs.